Variable speed governor

ABSTRACT

A variable speed governor for a pressurized fluid engine having a pressurized fluid supply means to the engine, a pressure operated valve for controlling the fluid supply and including a valve member movable between open and closed positions, a fluid conduit for providing fluid pressure to the operating portion of the valve for moving the valve toward its closed position on increasing pressure on the valve member, a vent for venting fluid away from the valve operating portion, a device for interrupting or blocking the venting as a function of increasing speed of the engine to govern the engine speed, and a flow control device in addition to the interrupting means for controlling the maximum quantity of fluid capable of flowing through the vent and thereby the maximum speed of the engine.

United States Patent Theis, Jr. et al.

VARIABLE SPEED GOVERNOR Inventors: James V. Theis, Jr., Delray Beach Lynn M. Davis, Boca Raton, both of Fla.

Assignee: Hollymatic Corporation, Park Forest, 111,

Filed: Feb. 4, 1972 Appl. No.: 223,429

Related U.S. Application Data Continuation-impart of Ser. No. 167,644,, July 30, 1971, Pat. No. 3,708,240.

U.S. Cl 415/36, 415/30, 415/40, 137/56, 32/27 Int. Cl. F0lb 25/06 Field of Search 415/25, 36, 40, 30; 137/48, 56; 32/27 References Cited UNITED STATES PATENTS 8/1972 Cameron 137/56 2/1960 Conklin et a1. 415/36 8/1966 Stockton et a1 137/56 3,578,872 5/1971 McBurnie 415/25 Primary ExaminerC. J. Husar AttorneyAxel A. l-lofgren et al.

[57] ABSTRACT A variable speed governor for a pressurized fluid engine having a pressurized fluid supply means to the engine, a pressure operated valve for controlling the fluid supply and including a valve member movable between open and closed positions, a fluid conduit for providing fluid pressure to the operating portion of the valve for moving the valve toward its closed position on increasing pressure on the valve member, a vent for venting fluid away from the valve operating portion, a device for interrupting or blocking the venting as a function of increasing speed of the engine to govern the engine speed, and a flow control device in addition to the interrupting means for controlling the maximum quantity of fluid capable of flowing through the vent and thereby the maximum speed of the engme.

10 Claims, 7 Drawing Figures PATENTEU 0B! 2 3 I915 SHEET 10F 2 VARIABLE SPEED GOVERNOR CROSS REFERENCE TO RELATED APPLICATION FIELD OF THE INVENTION One of the features of this invention is to provide an improved fluid driven engine in which the flow of pressurized fluid thereto is controlled by a valve that is responsive to increasing fluid pressure in a chamber on the side of the valve opposite a valve seat and with means for increasing fluid pressure in this chamber with increasing rotational speed by blocking venting of the chamber so that pressure build-up in the chamber moves the valve toward closed position together with a device for varying the maximum flow rate from the chamber to determine the maximum speed of the englne.

DESCRIPTION OF THE PRIOR ART The most pertinent prior art of which applicants are aware are U.S. Pats. Nos. 1,704,403; 2,674,229; 3,242,936 and 3,552,410.

BRIEF DESCRIPTION OF THE DRAWINGS position of FIG. 1 and the fully open position of FIG.

FIG. 4 is an enlarged sectional exploded view of the speed responsive portion of both embodiments of the governor.

FIG. 5 is a sectional view taken substantially along line 5-5 of FIG. 4.

FIG. 6 is a transverse view taken-substantially along line 6--6 of FIG. 2.

FIG. 7 is a plan view of the orifice, member of the FIG. 3 embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pressurized fluid engine illustrated in the drawings is similar to the one described and claimed in the copending Theiset al application, Ser; No. 170,234,

filed August 9, 1971,,now U.S. Pat; No. 3708,24], and;

assigned to the same assigneeas thepresent application. Thus the engine10comprises a casing 11 in which is rotatably mounted a shaft l2 which in this embodiment has asmall abrasive grindingwheel 13' on its forwardend.

The rear of the ,casingll is provided with an axial tubular'extension l4:integral with and extending rearwardly of a rear cover 15. Attached to this rearwardly extending tube 141 is the end: 16 of a flexible. compressed air hose as a pressurizedfluid supply means to the engine.

The inner surface of the rear cover 15 is flat as shown at 17 in the area surrounding a fluid inlet or compressed air passage 18 in the tube 14.

The rear end of the casing 11 is enlarged and of circular cross section to provide a chamber 19 containing a rotor 20 that is attached to the threaded rear end 21 of the drive shaft 12. The shaft 12 is held for rotation within the casing by a pair of ball bearing devices 22 positioned at opposite ends of the shaft; 12 and of which only one is shown.

Compressed air or other pressurized fluid is admitted from the inlet passage 18 into the interior 24 of the rotor 20 through a passage 23 which communicates in its central area with the interior 24 of the rotor. Rotation producing power is imparted to the rotor 20 by the pressurized fluid operating within the rotor and ejected through a pair of fluid exit passages 25 which are positioned diametrically opposite each other in the circular cross section rotor 20 but of which only one is illustrated in FIG. 1. The air from the exit passages 25 flows through the chamber 19 toward the rear cover 15 and from there to the exterior through a plurality of openings 26 in the cover 15.

Surrounding the fluid inlet passage 18 and around which the rotor 20 rotatesin an annular floating seal 27 having a rear surface 28 bearing in sealing engagement with the surface 17 on the end cover 15 and a forward surface 29 subjected to air pressure in a pressurized fluid chamber 30.

The structure described above and illustrated in the drawings is described-in more detail and claimed in the above copending Theis et al U.S. Pat. No. 3708,,241.

In order to control the speed of rotation of the rotor 20 and thus the drive shaft 12 and the grinding wheel 13 thereon there is provided a governor device having a valve seat ring 31 of metal press fitted into the cylindrical surface 32 that is concentric to the axis of rotation and that also contains at its forward end the floating seal 27. This valve seat is generally cylindrical like the floating seal 27 and has a central passage 33'substantially coinciding with the central passage 34 in the seal 27. The ring 31 therefore defines the inner side of the fluid pressure chamber 30. Extending diametrically across the ring 31 is a metal rod 35 which functions as a barrier for diverting small particles that might be carried by the fluid 37 from entering the small governor fluid opening 55. It also acts to retain the ring in position. The opening 55 is small; thus in one embodiment it was only 0.0135 inch in diameter.

Cooperating with the valve seat surface 36 of the ring 31 to control pressurized fluid 37 flow through the concentric passage 18, seal passage 34 and ring passage 33 and thus the speed of the engine there is provided a Iongitudinally'extending valve member 38 of generally cylindrical shape that is coaxial with the axis of rotation of the shaft 12. The generally cylindrical valve 38 is movable in an axial chamber 39 in the shaft 12 and has a flat rear end 40 that engages the valve seat surface 36 to. block completely flow of the pressurized fluid 37 when the valve is completely closed against the. valve seat surface 36. This surface 40 is circular and has a diameter somewhat greater than the diameter of the central passage 33 in the ring 31 with which it is concentric.

At the forward end of the axial cylindricalchamber wardmost position to admit the maximum flow of pressurized fluid into the interior 24 of the rotor.

The valve 38 is movable in its cylindrical axial chamber 39 on two sets of spaced ball bearings 43 that roll on the inner surface of the chamber 39 during the movement of the valve 38 between its extreme positions of FIGS. 1 and2.

In order to prevent escape of fluid 37 forwardly in the chamber 39 from the inlet passage 23 to rotor interior 24 and also rearwardly from chamber 53 there is provided a transverse seal adjacent the rear end of the valve 38. In the illustrated embodiment this seal is made up of two discs 44 of leather held in a circumferential groove 45 in the valve and separated by a rigid spacer disc 46.

The valve 38 is constructed of a central metal stem 47 having the enlarged rear end provided with the flange 42 and a portion forwardly thereof within a rigid plastic sleeve 48 in which are located the two sets of circularly arranged radial openings 49 in which are located the sets of balls 43. The forward end of the stem 47 is provided with a metal insert 50 having a circular flange 51 against which bears one end of a compressed helical compression spring 52. This spring is precompressed so that when the fluid engine is under no fluid pressure the spring holds the valve 38 closed against ring 31 as illustrated in FIG. 1.

The axial chamber 39 in which the valve 38 is located provides at its forward end a chamber 53 in which the compressed spring 52 is positioned. In order to provide flow of fluid to this chamber 53 the stem 47 and the insert 50 are provided with a longitudinally extending axial fluid flow passage means 54 as a fluid conduit means that extends from a restricted entrance rear end 55 that is adjacent the valve seat 36 to a forward end in the insert 50 which communicates with the spring chamber 53. The end 55 of the passage 54 is restricted so as to predetermine the volume of fluid that is diverted from the passage 23 into the fluid pressure chamber 53.

Thus the valve operating chamber 53 is on the side or end of the valve 38 opposite the valve seat 36. Pressurized fluid in this chamber 53 acts in conjunction with the compression spring 52 on the portions of the valve forwardly of the gaskets 44 as a valve operating portion to urge the valve 38 toward the closed position of FIG. 1 or to the right as viewed in enlarged detail in FIGS. 2 and 3.

In order to control the valve closing fluid pressure in the chamber 53 there is provided vent means for venting this chamber as a result of centrifugal force. This vent means comprises a forward end closure plug 56 that is pressfitted into the forward end of the axial chamber 39. This metal plug 56 has a vent passage therein that includes a side passage 57 down the side of the plug, a radially inwardly extending passage 58 into an inner chamber 59 and a forwardly extending passage 60 that leads into a forward chamber 61 which is connected by a radial passage 62 to an annular fluid passage 63 between the shaft 12 and the casing 11.

The forward end of the plug 56 is sealed to the surface of the forward end of the chamber 39 by means of a gasket 64 held in a circular groove 65. 6

In order to provide centrifugal responsive means for interrupting and thereby controlling the venting of pressurized fluid from the chamber 53 the inner chamber 59 of the plug 56 is provided with a closure plug 66 that is spaced from the end of the inner chamber 59 surrounding the radial passage 58 so as to provide communications between the passages 58 and 60. This inner end of the closure plug 66 is provided with a recessed chamber 67 extending generally radially and communicating at its inner end with a passage 68 substantially parallel to the passage 60 and also in communication with the chamber 61. Positioned in this radial chamber 67 is a metal ball 69 that is adapted to seat against the inner end 70 of the radial passage 58 when thrown outwardly by the centrifugal force of the rotating shaft 12. Thus the position of the ball 69 controls venting of fluid to a region 63 of normal atmospheric pressure through the passages 57, 58, 60 and 62 from the chamber 53. The region to the rear of the ball or the top as illustrated in the drawings is vented also to the chamber 61 by way of the passage 68. Thus the ball 69 in conjunction with the structure associated therewith comprises-centrifugally responsive means for restricting or interrupting flow of valve control fluid from the vent means 57-62 as a function of increasing rotational speed and thereby having the net effect of increasing the pressure of the valve control fluidin the chamber 53. Any increase in pressure in this chamber of course acts in conjunction with the spring 52 to urge the valve'member 38 rearwardly or to the right as illustrated and cooperate with the valve seat surface 36 in controlling flow of fluid 37 into the interior 24 of the rotor 20..In those cases where fluid pressure in rotor interior 24 is relatively low compared to fluid pressure in inlet area 71 there is no need for spring 52.

The axial chamber or bore 39 in the shaft 12 in which the axially movable valve 38 and associated structure are located is concentric with the axis of rotation and with the valve, valve seat 31, floating seal 27 and pressurized fluid supply passage 18.

In the first embodiment of FIGS. 1 and 2 there is provided a flow control means in addition to the centrifugally operated interrupting means which is embodied in the axially movable metal ball 69 and its seat 70. This flow control means in this first embodiment comprises a threaded insert 72 at the outer end of the vent passage 60 with this insert having an orifice passage 73 located substantially centrally therein. This orifice passage 73 limits the maximum flow of fluid vented from the chamber 53 by way of the passages and chambers 57-62 to the atmosphere by way of cylindrical chamber 63 which itself is vented to the atmosphere. The size ofthe oriflce 73 determines the rate of flow of this vented fluid and thus the maximum speed of operation of the engine 10 which will occur when the valve 38 is in fully open position as illustrated in FlG. 2.

In order to provide for replacement of each threaded insert 72 with one of a different size orifice 73 an access passage 74 is provided through the casing 1 1 to expose the outer end of the threaded insert 72. Thus in order to change the insert and thereby regulate the size of the orifice 73 and the resulting maximum speed of the engine it is only necessary to turn the rotor shaft 12 until the insert 72 is aligned with the passage 74 as shown in FIG. 2, unscrew the insert 72 and replace it with another having a different size orifice passage 73.

In the embodiment of FIGS. 3 and 7 the threaded insert 172 has an elongated orifice passage 173 which is blocked to the extent desired by rotating a threaded sleeve on the outer surface of the shaft 12 at the portion containing the insert 172. As can be seen in FIG.

3 the position of the threaded sleeve 75 relative to the insert exposes the desired portion of the orifice passage 173 so that fluid can flow from the vent passage 62 and through the orifice passage 173 by way of an auxiliary passage 76 at the forward end of the sleeve 75 and communicating with the orifice passage 173. Preferably there is also provided a set screw (not shown) extending through the sleeve 75 to lock it in adjusted position during operation of the engine. Thus the rotatable sleeve 75 in this embodiment provides a similar adjustment to a series of threaded inserts 72 in the first embodiment each having a different size orifice but with the sleeve 75 the individual adjustments are infinite in number.

The operation of the governor is as follows. When the fluid engine is at rest and subjected to no fluid pressure in the inlet passage 18 the valve 38 under the urging of the spring 52 is in closed position as shown in FIG. 1 with the valve surface 40 in engagement with the valve seat surface 36. Immediately upon pressurized fluid 37 such as compressed air being supplied through the passage 18 the pressure of this fluid initially forces the valve 38 fully to the left as shown in FIG. 2 to engage the annular flange 42 with the circular step 41 which acts as a motion limiting stop. While this is occurring for the brief moment fluid from the inlet area 71 flows through the passage 54 in the valve 38, into the spring chamber 53 and through the passage 57-62. Immediately, however, the pressure of the fluid in the rotor interior 24 begins rotation of the rotor and thus the shaft 12 to which it is attached and the resulting centrifugal force urges the weighted member ball 69 outwardly toward its seat 70. This blockingof the vent passage from the chamber 53 in conjunction with the compressed spring52 moves the valve 38 to the right from the position shown in FIG. 2 due to the buildup of back pressure in the chamber 53. the rotating rotor and shaft thereupon achieve a governed speed and at this speed the valve. 38 and the parts associated therewith are in the intermediate position shown in FIG. 3.

If there is a tendency for the speed to increase then the ball 69 will move into closer engagement with its valve seat 70 to build up the back pressure in the chamber 53 and urge the valve further to the right to restrict the fluid flow to the rotor to a greater degree and thus slow down the rotation. If, however, the rotational speed should tend to drop such as by placing a heavier load on the grinder wheel 13 the centrifugal force on the ball 69 would drop thereby causing fluid flow to move it away from the seat 70 and permit more air to be vented from the back pressure chamber 53 which would permit the valve 38 to move to the left and supply more pressurized fluid 37 to the interior 24 of the rotor.

In the embodiments of both FIG. 2 and FIG. 3 the maximum speed of rotation when the valve 38 is fully open iscontrolled by the size of the vent passage which vents thechamber 53 which in turn is controlled by the size of'the orifices 73 and 173. Thus in one embodimentwith compressed air at 80 psi supplied by the fluid inlet passage 18 the pressure in the valve operating chamber 53 was found to be about 60 psi. When the vent orifice illustrated at 73 was varied between 0.016

and 0.024 inch diameter the maximum rpm varied between 30,000 and 70,000. In the absence of a governor 38,.the maximum speed of a typical pressurized air tool ofthe type illustrated can be as high as 140,000 rpm.

By using a governor having the movable valve member illustrated at 38 this maximum speed is controlled to about 70,000 rpm. By using the orifices as illustrated at 73 and 173 to control the venting of the chamber 53 the maximum speed can be further reduced below this in the manner illustrated. Thus the governor and the maximum speed controls of this invention provide a more stable engine and one where the speed attained is precisely that required for the particular use of the engine. v

The function of the back pressure vent means of this invention is believed to be as follows although the invention is not limited to any particular theory of operation. The fluid back pressure in the chamber 53 which operates on the valve 38 to urge it toward closed position or to the right in FIGS. 2 and 3 is a value that varies only slightly during the full range of operation of the engine. Thus in the embodiment illustrated the design pressure selected in the chamber 53 was about 60 psi with an air supply through the passage 18 of about psi. This means that when the pressure in the chamber 53 reaches 60 psi the valve 38 begins moving toward closed position. or to the right as illustrated. Regardless of the position of the valve 38 the air supply to the chamber 53 does not change because the opening 55 to the passage 54 does not vary. Therefore, the only factor that can have an effect on the pressure in the chamber 53 is the back pressure that is controlled by the proximity of the centrifugally operated ball valve 69 to its seat 70. This of course is only true so long as the vent passages downstream of the ball 69 are free.

The changes in pressure in the chamber 53 are very small for all positions of the valve 38 between fully open as shownin FIG. 2 and fully closed as shown in FIG'. 1. For example with the design pressure of 60 psi in chamber 53 the valve 38 is in the intermediate position as shown in FIG. 3. At about 59 psi the valve 38 tends to move all the way to the left or completely open as shown in FIG. 2. When the pressure in the chamber 53 reaches 62 psi the valve 38 is moved all the way to the right or to fully closed position as shown in FIG. 1. Therefore in this embodiment the range between fully open and fully closed is only from about 59-62 psi or a range of only 3 psi total. This range and these pressure conditions do not change during operation of the governor.

What does change during the operation of the governor is the pressure in the vent means downstream of the centrifugally operated ball 69 or the pressure in the vent passage including the passages 59-62 and 67-68. Thus the back pressure or the valve operating pressure flows to the chamber 53 by way of passages 55 and 54,

thenflows through the passages 57, 58, 59, 60, 61, 62 i and 68 past the ball69 and then out through the vent orifice 73 or 173 in the insert 72 or 172. In the illustrated embodiment the opening 55 is 0.0135 inch and the tapped hole that contains the insert 72 or 172 is one-sixteenth inch in diameter. The function of the orifice passage 73 or 173 is to control the rate of flow of vented fluid and thus the fluid pressure downstream of chamber 53 which is as previously described. However, because of the control of the back pressure on the downstream side of the ball the effect on the ball is quite drastic. Thus the upstream pressure on the ball or the pressure from the chamber 53 remains, for example, 60 psi. However, the pressure on the downstream side of the ball which would be zero without the presence of the insert 72 is now 20 psi, for example, because of the orifice 73 or 173. This means that the net pressure on the upstream side of the ball 69 or the side adjacent the chamber 53 is now 60 minus 20 or a net of 40 psi on the side of the ball adjacent the chamber 53. This means that the pressure in the chamber 53 required to close the valve 38 completely can be achieved with a greatly reduced centrifugal force acting on the ball and therefore at for example 60 psi in the chamber 53 with the presence of the orifice 73 the closing force will be equivalent to an rpm of 30,00070,000 dependent upon the size of the orifice 73. The larger the orifice the higher the maximum speed.

The presence of the orifice illustrated at 73 and at 173 does not change the response of the engine to any degree. In other words, if at a maximum speed of 70,000 rpm the engine requires a drop of 2,000 rpm to open the valve 38 completely as illustrated in FIG. 2 the lower maximum rpm with the orifice 73 present still requires a drop of 2,000 rpm even when the maximum rpm is, for example, only 30,000. The only thing that occurs with the vent orifice 73 is to change the maximum rpm that the engine can develop. As an example the 0.024 inch diameter hole 73 provides a maximum rpm of about 60,000 while reducing this diameter to 0.018 inch reduces the maximum rpm to 40,000.

In a typical embodiment the centrifugal ball 69 was of one-sixteenth inch diameter and the ball weighed 3.67 X pounds. At 80,000 rpm the center of the ball was 0.0I9 inch from the axis of rotation and at this speed the ball was spaced about 0.001 inch from its circular seat 70.

When the valve 38 is closed as shown in FIG. 1 where it is subjected to no incoming pressurized fluid the seal surface 40 overlaps and extends completely across the opening 33 defined by the inner surface of the valve seat ring 31. When the pressurized fluid indicated at 37 enters through theinlet passage 18 it bears against the valve surface 40 and pushes it away from the valve seat 36. This immediately causes the incoming pressure to bear against a larger transverse surface of the valve than the seal surface 40 because now the fluid 37 can flow around the circular flange 42 and bear against the seal 44 which extends annularly beyond the seal surface 40 as shown most clearly in FIGS. 2 and 3. This means that the total force on the valve urging it away from its position of FIG. 1 toward the fully extended position of FIG. 2 is greater because the surface acted upon by this pressure is greater.

The incoming pressurized fluid 37 initially moves the valve 38 all the way to the left as viewed in FIG. 2 until the flange 42 bears against the shoulder 41 as shown in FIG. 2. Immediately most of the fluid is directed radially outwardly into the interior 24 of the rotor whereupon rotation commences. At the same time some of the fluid flows through the passages 55 and 54 into the chamber 53 to create a back or closing pressure on the forward or left end of the valve 38 which counteracts the fluid pressure on the rear or valve seal surface end 40 of the valve. This back pressure in the chamber 53 in conjunction with the spring 52 tends to urge the valve 38 in a reverse or closed direction and at some point depending upon the speed of rotation of the rotor 20 and the attached shaft 12 and associated structure the valve 38 will assume an intermediate governed position between fully open and fully closed position as illustrated for example in FIG. 3.

In the speed governor of this invention the forces on the valve are balanced so that the operation of the valve is smooth and responds immediately to differences in load and in speed. Thus when the valve 38 moves to the right toward its closed position the fluid pressure on the face 40 of the valve increases because less fluid can bypass the valve seat 36 into the interior 24 due to the lessening space. This lessened fluid flow into the rotor interior 24 decreases the pressure in this space 24 and at the same time fluid pressure on the annular seal 44 also decreases. Simultaneously the closing force of the precompressed spring 52 also decreases as the spring becomes elongated with the valve moving toward its closed position. The resultant of all these forces is that the decreasing forces do not completely offset the above-described increasing force on the face 40 of the closing valve so that as the valve moves toward its closed'position there is a slight increase in the net forces acting on the valve. This means that the valve operation is smooth when moving toward its closed position and achieving a balanced position such as illustrated in FIG. 3. The differences in rpm of the rotor and thus of the shaft 12 under varying loads is quite small. Thus at an operating speed of 50,000 rpm the difference in speed between low and heavy loads was only about 50 rpm.

From the above it can be seen that the governor operates by controlling the fluid supply from the passage 18 to operate the rotor 20. The governor is thus applicable to any pressurized fluid operated device where fluid (either gas or liquid) is used to operate a power device.

The valve 38 acts as a throttle valve to restrict this fluid flow when necessary and a portion of the pressurized fluid supplied to the engine is diverted to function as a valve closing force in conjunction with a compressed spring and with this diverted fluid being either vented so as to reduce its effect or being confined. as required with this venting being controlled by the centrifugal forces set up in a weighted member ball 69.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is out intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the appended claims.

We claim:

1. A variable speed governor for a pressurized fluid engine, comprising: a rotor, a rotatable drive shaft driven by said rotor; pressurized fluid supply means to said engine rotor; a speed control valve having a valve seat and a cooperating valve member in said supply means movable between open and closed positions for controlling the fluid supply to said engine rotor and thereby the speed of said rotor and shaft, said valve member having a valve operating portion; fluid conduit means for providing fluid pressure to. said valve operating portion for moving said valve toward its said closed position, said fluid conduit means comprising a fluid conduit having an entrance at said pressurized fluid supply means and an exit at said valve operating portion; vent means for venting said fluid conduit means; interrupting means for interrupting said venting as a function of the speed of said engine rotor and thereby increasing the force of said fluid pressure on said valve operating portion upon increase in said speed; and flow control means in addition to said interrupting means for controlling the maximum quantity of fluid flowing through said vent means and thereby the maximum speed of said engine.

2. The governor of claim 1 wherein said conduit comprises a conduit portion extending through said valve member.

3. The governor of claim 1 wherein said means for interrupting comprises centrifugally operated valve means in series with said valve member for flow of said vented fluid successively past said speed control valve and through said centrifugally operated valve means.

4. A variable speed governor for a pressurized fluid engine, comprising: a rotor; a rotatable drive shaft driven by said rotor; pressurized fluid supply means to said engine rotor; a speed control valve having a valve seat and a cooperating valve member in said supply means movable between open and closed positions for controlling the fluid supply to said engine rotor and thereby the speed of said rotor and shaft, said valve member having a valve operating portion; fluid conduit means for providing fluid pressure to said valve operating portion for moving said valve toward its said closed position; vent means for venting said fluid conduit means; interrupting means for interrupting said venting as a function of the speed of said engine rotor and thereby increasing the force of said fluid pressure on said valve operating portion upon increase in said speed; flow control means in addition to said interrupting means for controlling the maximum quantity of fluid flowing through said vent means and thereby the maximum speed of said engine; and a fluid chamber at said valve operating portion, said fluid conduit means for providing fluid pressure to said operating portion extending to said chamber and said vent means extending from said chamber.

5. The governor of claim 4 wherein said means for interrupting said venting comprises a centrifugally responsive closure in said vent means at a location.

therein between said chamber and said flow control means.

6. A variable speed governor for a pressurized fluid engine, comprising: a rotor; a rotatable drive shaft driven by said rotor; pressurized fluid supply means to said engine rotor; a speed control valve having a valve seat and a cooperative valve member in said supply means movable between open and closed positions for controlling the fluid supply to said engine rotor and thereby the speed of said rotor and shaft, said valve member having a valve operating portion; fluid conduit means for providing fluid pressure to said valve operating portion for moving said valve toward its said closed position; vent means for venting said fluid conduit means; interrupting means for interrupting said venting as a function of the speed of said engine rotor and thereby increasing the force of said fluid pressure on said valve operating portion upon increase in said speed; and flow control means in addition to said interrupting means for controlling the maximum quantity of fluid flowing through said vent means and thereby the maximum speed of said engine, said flow control means comprising a replaceable orifice member having an orifice therein. 1

7. The governor of claim 6 wherein said fluid conduit means for providing fluid pressure to said valve operating portion comprises a fluid conduit having an entrance at said pressurized fluid supply means and an exit at said valve operating portion.

8. The governor of claim 6 wherein said conduit comprises a conduit portion extending through said valve member and wherein said means for interrupting comprises centrifugally operated valve means in series with said valve member for flow of said vented fluid successively past said speed control valve and through said centrifugally operated valve means.

9. The governor of claim 6 wherein there is provided a fluid chamber at said valve operating portion, said fluid conduit means for providing fluid pressure to said operating portion extends to said chamber and said vent means extends from said chamber.

10. The governor of claim 9 wherein said means for interrupting said venting comprises a centrifugally responsive closure in said vent means at a location therein between said chamber and said flow control means. 

1. A variable speed governor for a pressurized fluid engine, comprising: a rotor; a rotatable drive shaft driven by said rotor; pressurized fluid supply means to said engine rotor; a speed control valve having a valve seat and a cooperating valve member in said supply means movable between open and closed positions for controlling the fluid supply to said engine rotor and thereby the speed of said rotor and shaft, said valve member having a valve operating portion; fluid conduit means for providing fluid pressure to said valve operating portion for moving said valve toward its said closed position, said fluid conduit means comprising a fluid conduit having an entrance at said pressurized fluid supply means and an exit at said valve operating portion; vent means for venting said fluid conduit means; interrupting means for interrupting said venting as a function of the speed of said engine rotor and thereby increasing the force of said fluid pressure on said valve operating portion upon increase in said speed; and flow control means in addition to said interrupting means for controlling the maximum quantity of fluid flowing through said vent means and thereby the maximum speed of said engine.
 2. The governor of claim 1 wherein said conduit comprises a conduit portion extending through said valve member.
 3. The governor of claim 1 wherein said means for interrupting comprises centrifugally operated valve means in series with said valve member for flow of said vented fluid successively past said speed control valve and through said centrifugally operated valve means.
 4. A variable speed governor for a pressurized fluid engine, comprising: a rotor; a rotatable drive shaft driven by said rotor; pressurized fluid supply means to said engine rotor; a speed control valve having a valve seat and a cooperating valve member in said supply means movable between open and closed positions for controlling the fluid supply to said engine rotor and thereby the speed of said rotor and shaft, said valve member having a valve operating portion; fluid conduit means for providing fluid pressure to said valve operating portion for moving said valve toward its said closed position; vent means for venting said fluid conduit means; interrupting means for interrupting said venting as a function of the speed of said engine rotor and thereby increasing the force of said fluid pressure on said valve operating portion upon increase in said speed; flow control means in addition to said interrupting means for controlling the maximum quantity of fluid flowing through said vent means and thereby the maximum speed of said engine; and a fluid chamber at said valve operating portion, said fluid conduit means for providing fluid pressure to said operating portion extending to said chamber and said vent means extending from said chamber.
 5. The governor of claim 4 wherein said means for interrupting said venting comprises a centrifugally responsive closure in said vent means at a location therein between said chamber and said flow control means.
 6. A variable speed governor for a pressurized fluid engine, comprising: a rotor; a rotatable drive shaft driven by said rotor; pressurized fluid supply means to said engine rotor; a speed control valve having a valve seat and a cooperative valve member in said supply means movable between open and closed positions for controlling the fluid supply to said engine rotor and thereby the speed of said rotor and shaft, said valve member having a valve operating portion; fluid conduit means for providing fluid preSsure to said valve operating portion for moving said valve toward its said closed position; vent means for venting said fluid conduit means; interrupting means for interrupting said venting as a function of the speed of said engine rotor and thereby increasing the force of said fluid pressure on said valve operating portion upon increase in said speed; and flow control means in addition to said interrupting means for controlling the maximum quantity of fluid flowing through said vent means and thereby the maximum speed of said engine, said flow control means comprising a replaceable orifice member having an orifice therein.
 7. The governor of claim 6 wherein said fluid conduit means for providing fluid pressure to said valve operating portion comprises a fluid conduit having an entrance at said pressurized fluid supply means and an exit at said valve operating portion.
 8. The governor of claim 6 wherein said conduit comprises a conduit portion extending through said valve member and wherein said means for interrupting comprises centrifugally operated valve means in series with said valve member for flow of said vented fluid successively past said speed control valve and through said centrifugally operated valve means.
 9. The governor of claim 6 wherein there is provided a fluid chamber at said valve operating portion, said fluid conduit means for providing fluid pressure to said operating portion extends to said chamber and said vent means extends from said chamber.
 10. The governor of claim 9 wherein said means for interrupting said venting comprises a centrifugally responsive closure in said vent means at a location therein between said chamber and said flow control means. 